1. Field of the Invention
This invention relates to the field of composting of organic matter to produce fertilizers. More specifically, this invention pertains to a method and apparatus for converting the residue from grape and fruit juice producing processes into a high grade fertilizer and for recovering the heat and carbon dioxide produced from the decay of such residues.
2. Description of the Prior Art
The search for high grade humus or fertilizers is a continuing one. A number of natural fertilizers are known as well as, of course, chemically synthesized fertilizers. All of these are, however, either in short supply due to difficulties in obtaining starting materials or because of the relatively low supply of materials to ferment into natural fertilizers. In searching for new starting materials for obtaining humus, marc or pressing residues from wine making were considered. Generally, in the wine making art, the marc which accumulates in relatively large quantities is considered an unsuitable commodity and is generally moved and disposed of. One of the reasons is that during the degradation phase of such marc residues, these materials are highly incompatible with plant root systems because of the aggressiveness of the participating microbes within the decaying marc and the metabolic products which are produced therefrom. As a result, it has not previously been considered to utilize marc and other pressing residues from fruit juice production as fertilizers. Also, and particularly with respect to the wine growing industry, extensive sums are spent for disposing of marc accumulations which, heretofore, have served no useful purpose.
The demand for organic fertilizers is quite high and since such fertilizers possess much more desirable ecological behavior than the chemically or synthetically produced fertilizers, the ability to produce high grade natural or organic fertilizers would be of great economic importance. With respect to marc, it should be noted that the world production of grapes is larger than the negotiable world harvest of bananas, oranges, and apples, taken together. Eighty-five percent of these grapes are processed into wine, sparkling wine, and unfermented grape juice. About twenty percent of the weight of these grapes remains behind as the marc.